Speaker
Description
SrMnO3 can be strain-engineered to be multiferroic, with coexisting and tuneable magnetic and ferroelectric (FE) order. We recently showed, using first principles calculations, that the ferroic strain-temperature phase diagram of SrMnO3 accommodates a tetracritical point (TCP) with coinciding magnetic and FE ordering temperatures.
Here, we construct a Landau theory with parameters determined from first principles DFT and effective Hamiltonian calculations, and demonstrate large magnetoelectric coupling, several orders of magnitude larger than in conventional magnetoelectrics, occurring near the TCP. We study a giant magnetic cross-caloric effect, increasing the electrocaloric effect by 60%, providing an example of a large, useful magnetoelectric coupling effect in an antiferromagnetic multiferroic. This opens new possibilities for promising research directions among caloric effects for solid state cooling.
